Relationship between changes in real-world arm use behavior and structural remodeling of white matter after ischemic stroke

Abstract

Background: Although associations between changes in upper-extremity motor impairment and structural changes in white matter after a stroke have been reported, no studies have been conducted to investigate the relationship between changes in real-world arm use and structural changes in white matter after a stroke. Objective: To investigate the correlation between changes in real-world arm use and white matter structure after an ischemic stroke. Methods: In the subacute phase after an ischemic stroke, 18 patients with upper-extremity paralysis underwent the clinical assessments (Fugl-Meyer assessment-upper extremity [FMA-UE] and Motor Activity Log [MAL]) before and after rehabilitation. Neural pathway integrity was also assessed using fractional anisotropy (FA) in diffusion tensor imaging. We assessed the correlation between changes in FA and clinical assessments. A similar sub-analysis was performed on 11 patients with moderate to severe paralysis. Results: Changes in FMA-UE did not correlate with changes in FA in each region of interest. However, changes in the MAL were positively correlated with changes in FA in the column and body of the fornix (r=0.699, p=0.017) and the ipsilesional posterior limb internal capsule (r=0.640, p=0.034) in sub-analysis. Furthermore, there was a tendency towards a correlation in the ipsilesional cingula of the cingulate gyrus in all patients (r=0.441, p=0.067) and in patients with moderate to severe paralysis (r=0.544, p=0.083). Conclusions: Changes in real-world arm use after an ischemic stroke may be associated with changes in the corticospinal tract and white matter structures, such as the fornix and cingulate, related to the reward system and behavioral learning.